Device for conveying and checking containers, in particular preforms

ABSTRACT

A device ( 1 ) for conveying and checking containers, in particular preforms, comprises an infeed and accumulation section ( 2 ) for containers arriving from a forming station and a carrousel ( 3 ) located downstream of the infeed and accumulation section ( 2 ) in the direction of feed of the containers, to feed the containers thorugh a sequence of checking stations ( 4 ) disposed in the periphery of carrousel ( 3 ). The infeed section is intermittently supplied with containers by the forming station while the carrousel ( 3 ) turns continuously. An endless chain ( 5 ) extends along a path defined by driving gear-wheels ( 6 ) which partially overlaps the infeed and accumulation section ( 2 ) and the circular trajectory of the carrousel ( 3 ). A first and second driving gearwheels (9 a,  9 b ) positioned along the path followed by the endless chain ( 5 ) are mobile to compensate the variations in the length of a delivery section and a return section of the chain ( 5 ).

TECHNICAL FIELD AND BACKGROUND ART

[0001] The present invention relates to a device for checkingcontainers, in particular preforms.

[0002] The device is included in the sector of bottling systems,substantially at the start of the production line.

[0003] As is known, plastic bottles for bottling are made by means ofseveral successive processes which include, firstly, the formation ofthe so-called preforms and, secondly, preform blowing to obtain thefinished bottle.

[0004] The preforms are cylindrical containers in which the mouth, neckand threaded portion of the neck already have their final dimensions,whilst the bottle body is cylindrical and has substantially the samediameter as the neck. The preforms are then transferred to a blowingmachine, in which they are inserted in a mould with the final shape anddimensions of the bottle.

[0005] The preforms are formed by moulding with intermittent production,using a mould with a set of cavities arranged in rows. The mould istilted to unload a row of preforms onto a conveyor which links theforming station and the subsequent blowing station.

[0006] The teachings of prior art have some important disadvantages.Firstly, the preforms moulded in rows inside the mould are tipped looseonto the conveyor belt. Then they are set upright again and arranged ina row before entering the blowing station.

[0007] This procedure involves the use of intermediate devices betweenthe forming station and the blowing station, which increase productiontimes and complicate plant layout.

[0008] Secondly, during the stage in which they are tipped onto theconveyor, the preforms are subject to impacts and damage which maycompromise the good condition of the final bottle and, as a result, giverise to rejects which affect the production cycle of the entire

TECHNICAL FIELD AND BACKGROUND ART

[0009] The present invention relates to a device for checkingcontainers, in particular preforms.

[0010] The device is included in the sector of bottling systems,substantially at the start of the production line.

[0011] As is known, plastic bottles for bottling are made by means ofseveral successive processes which include, firstly, the formation ofthe so-called preforms and, secondly, preform blowing to obtain thefinished bottle.

[0012] The preforms are cylindrical containers in which the mouth, neckand threaded portion of the neck already have their final dimensions,whilst the bottle body is cylindrical and has substantially the samediameter as the neck. The preforms are then transferred to a blowingmachine, in which they are inserted in a mould with the final shape anddimensions of the bottle.

[0013] The preforms are formed by moulding with intermittent production,using a mould with a set of cavities arranged in rows. The mould istilted to unload a row of preforms onto a conveyor which links theforming station and the subsequent blowing station.

[0014] The teachings of prior art have some important disadvantages.Firstly, the preforms moulded in rows inside the mould are tipped looseonto the conveyor belt. Then they are set upright again and arranged ina row before entering the blowing station.

[0015] This procedure involves the use of intermediate devices betweenthe forming station and the blowing station, which increase productiontimes and complicate plant layout.

[0016] Secondly, during the stage in which they are tipped onto theconveyor, the preforms are subject to impacts and damage which maycompromise the good condition of the final bottle and, as a result, giverise to rejects which affect the production cycle of the entire plant.

[0017] Moreover, in known bottling plant, the preforms are transferreddirectly from the forming machine to the blowing machine withoutintermediate checks on the good condition of the preforms and productionuniformity.

DISCLOSURE OF INVENTION

[0018] The aim of the present invention is, therefore, to overcome theabove-mentioned disadvantages by providing a device for checkingcontainers, in particular preforms, which picks up the preforms arrangedin rows and transfers them to successive stations, in particular to theforming station, avoiding any damage and superfluous transfers andrearrangement of the preforms.

[0019] Another aim of the present invention is to provide a device forchecking preforms which allows adaptation between the forming stationintermittent operation and the continuous operation of the plantdownstream of the forming station.

[0020] These aims are fulfilled by the device for checking containers,in particular preforms, disclosed whose characteristics are described inthe claims herein and, in particular, characterised in that it comprisesan infeed and accumulation section for the containers loaded alternatelyfrom a forming station, a continuously rotating carrousel and connectingmeans inserted between the infeed and accumulation section and thecarrousel and having means which adjust the alternate operation of theinfeed section relative to the continuous operation of the carrousel.

BEST MODE FOR CARRYING OUT THE INVENTION.

[0021] This and other characteristics are more clearly illustrated inthe detailed description which follows, with reference to theaccompanying drawing, which illustrate a preferred embodiment withoutlimiting the scope of application, and in which:

[0022]FIG. 1 is a top view of a device made in accordance with thepresent invention.

[0023] With reference to the accompanying drawing, the numeral 1indicates as a whole a device for checking containers, in particularpreforms.

[0024] The preforms are made by moulding in a forming station which isnot illustrated, being of the substantially known type. The formingstation has a mould in which the preforms are made in a plurality ofrows. The preforms are also unloaded from the mould with the mouthfacing downwards.

[0025] The forming station has alternating operation, since the preformsare unloaded from the mould one row at a time, whilst the forming stageis completed on the other rows. The figure illustrates a diagram of apossible layout of the device 1 in which the numeral 2 denotes an infeedand accumulation section for containers from the forming station. Thenumeral 3 indicates a carrousel which rotates continuously, feeding thecontainers through a sequence of checking stations 4. In particular,there is a station 4 a which checks the weight of the preforms andseveral reject stations 4 b in which faulty preforms are rejected.

[0026] The preforms are picked up from the forming station, inserted inthe infeed and accumulation station 2 and transferred to the carrousel3. This transfer is performed by an endless chain 5 extending along apath defined by driving gears 6.

[0027] The path followed by the chain 5 partially overlaps the circulartrajectory of the carrousel 3 for preform transfer.

[0028] Moreover, the endless chain 5 overlaps the container infeed andaccumulation section 2, defining four container reception rows 7,between three driving gears 6 a, 6 b and 6 c.

[0029] Each row 7 receives a row of preforms from the mould in theforming station. During loading of the reception rows 7 in the infeedand accumulation section, the section of chain which defines the rowsremains stationary between the driving gears 6 a, 6 b and 6 c. As soonas the four rows 7 are complete, the corresponding section of chainmoves forward while four new empty rows 7 are filled.

[0030] The endless chain 5 constitutes connecting means between theinfeed and accumulation section 2 and the carrousel 3 located downstreamof the infeed section in the direction of container feed. These meanscomprise means 8 which adjust the alternate operation of the formingstation relative to the continuous operation of the carrousel. Theseadjusting means 8 are designed to guarantee continuous sliding of thechain 5 in the section which overlaps the trajectory of the carrousel 3.

[0031] For this purpose, the adjusting means 8 comprise a first and asecond driving gear 9 a and 9 b. The first driving gear 9 a ispositioned along the path followed by the endless chain 5 on the sectionwhich passes from the infeed and accumulation section 2 to the carrousel3, whilst the second driving gear 9 b is positioned on the section whichreturns from the carrousel 3 to the infeed and accumulation section 2.

[0032] The first and second driving gears 9 a and 9 b are mobile,adjusting the variations in the length of the delivery and returnsection. In particular, the driving gears move parallel with the chainin the two sections, in the direction indicated in the figure.Obviously, whilst the first driving gear moves towards the carrousel 3to compensate the reduction in the length of the delivery section of thechain 5, the second driving gear 9 b moves away from the carrousel 3 tocompensate the increase in the length of the return section of the chain5.

[0033] As soon as the four rows 7 of the infeed and accumulation sectionare complete, the first and second driving gears 9 a and 9 b inverttheir motion. The preforms are transferred from the forming station tothe chain 5, with the mouths facing downwards, and this position ismaintained along the preform conveyor throughout the device 1. For thisreason, the chain 5 comprises retaining means which receive thecontainers from the forming station and feed them along the deliverysection from the infeed and accumulation section to the carrousel,keeping the containers with the mouths facing downwards. The containersare then transferred from the chain to the carrousel.

1. a device (1) for checking containers, in particular preforms,characterised in that it comprises: an infeed and accumulation section(2) for the containers arriving from a container forming station, theinfeed section being loaded alternately by the forming station; acarrousel (3) which rotates continuously, located downstream of theinfeed section in the direction of container feed, to feed thecontainers through a sequence of checking stations (4); connecting meanslocated between the infeed and accumulation section and the carrouseland having means (8) for adjusting the alternate operation of the infeedsection relative to the continuous operation of the carrousel.
 2. Thedevice according to claim 1, characterised in that the connecting meanscomprise an endless chain (5) extending along a path defined by drivinggears (6), the path partially overlapping the circular trajectory of thecarrousel.
 3. The device according to claim 2, characterised in that theendless chain (5) also overlaps the container infeed and accumulationsection (2), defining a plurality of container reception rows (7). 4.The device according to any of the foregoing claims, characterised inthat the adjusting means comprise a first and a second driving gear (9a, 9 b) arranged along the path followed by the endless chain, locatedrespectively on the delivery section of the infeed and accumulationsection to the carrousel and on the return section from the carrousel tothe infeed and accumulation section, the first and second driving gearsbeing mobile to compensate the variations in the length of the deliveryand return sections.
 5. The device according to any of the foregoingclaims from 2 to 4, characterised in that the chain comprises retainingmeans which receive the containers from the forming station and feedthem along the delivery section from the infeed and accumulation sectionto the carrousel, the containers being positioned with the mouths facingdownwards.
 6. The device according to any of the foregoing claims,characterised in that it comprises at least one reject station (4 b) foreliminating faulty preforms.
 7. The device according to any of theforegoing claims, characterised in that the checking stations (4)comprise at least one station (4 a) for weighing the containers.